Hi, you could try a vinegar based window cleaner on the discs, we find this works better than the best "disc cleaners". If that doesn't work the pads could be contaminated, it would be worth putting in a new set.
I had that on the halfords vengeance, even after cleaning with disc brake cleaner, didn't go away. Go vack to shop and ask them to replace pads with different type. Otherwise you have stones/ grit stuck to both pads. Very annoying isn't it.
Or could be they just have to bed in.
I have had it since day 1 on my rear brake but to be honest i find it more useful than a bell on the cycleways a quick dab of the brake and pedestrians tend to react quicker.
Try repeadly braking HARD on the affected brake - worked for me - I was always tentative with my front brake and, as a result, it never really got properly 'worn in' but this advice worked for me
Mine tend to squeak when they get wet.
Ignore it, as Amoto65 says, it is a useful warning device and probably a shriek of brakes is far more alarming to dozy dog walkers and earphone wearing air heads than a ting from a bell.